The present invention relates to a movement prevention structure for a shielded connector having a metal shell for an electric shield, and particularly to a movement prevention structure for a contact which connects the metal shell with a braided shield portion of a shielded wire and which is made of an electrically conductive material.
Conventionally, electromagnetic shielded connectors in which a metal case covers the outside of a resin housing or a metal plating is formed on the outside of a resin housing are often used. In such connectors, the metal case or the metal plating is exposed to the external environment, thereby producing a problem in that the metal case or the metal plating is rusted or corroded.
To cope with this, an embedded shielded connector has been proposed in which a metal shell is embedded by employing an integrally molding technique into a resin housing of an electromagnetic shielded connector.
FIG. 4 is a longitudinal section view showing a conventional embedded shielded connector under the state where the whole of the connector is assembled, and FIG. 5 is an enlarged view of a contact portion.
A housing 1 is made of a synthetic resin or the like. A substantial portion of a metal shell 3 is embedded into the housing. Only a part of the metal shell 3 is exposed as an exposed portion 3a on, for example, an inner periphery of a rear opening of the housing 1.
On the other hand, in a shielded wire 5, an inner sheath 9 is peeled off so that a conductor 11 is exposed, and a terminal 13 is clamped to be connected to the exposed conductor 11. A braided shield portion 15 is exposed in a position which is slightly rearward as compared with the leading end of the inner sheath 9. A contact (shield terminal) 17 having an annular clamp portion 17a is clamped to be connected to the braided shield portion 15. As shown in FIG. 5, the portion of the contact 17 which is behind the annular clamp portion 17a is increased in diameter so as to be formed as a contact portion 17b making contact with the exposed portion 3a.
As described above, the shielded wire 5 to which the terminal 13 and the contact 17 are clamped, is connected to the housing 1 by fitting the terminal 13 and the contact 17 into the housing 1. This causes the braided shield portion 15 and the exposed portion 3a to be electrically connected to each other through the contact 17 so as to constitute a magnetic shield wall covering the inner conductor. In the figures, 19 designates a rubber plug which is attached to the shielded wire 5 to seal a gap between the inner periphery of the housing and the shielded wire 5, and 21 designates a rear holder which holds the rubber plug 19.
However, the above-described conventional shielded connector has a problem as follows. When the fixing force exerted by the clamp connection of the contact 17 to the braided shield portion 15 is small, as shown by the arrow in FIG. 6, vibrations or the like cause the contact 17 to move toward the terminal 13 along a tapered face 23 (see FIG. 5) for guiding the insertion of a terminal, and the leading end of the contact 17 may make contact in some cases with the terminal 13 so that the terminal 13 and the braided shield portion 15 are short-circuited.